Blasting cartridge



June 15, 1937. F. H. ARMSTRONG BLASTING CARTRIDGE Filed nec. fr, 1954 INVENTOR. 'z'amH/fmsfony 'BY d 4,

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i Patented June. 15, 1937 `iJNl'lED STATI-:s

PATENT OFFICE BLASTING CARTRIDGE Illinois Application December 7, 1934, Serial No. 756,510

12 Claims.

This invention relates to blasting cartridges, and more particularly to blasting cartridges of the type in which a highly compressed gas is used as a blasting medium.l In the breaking of material, as in the breaking of coal from the Working face of a' mine wall, there are frequently conditions wherein rigid ,limitations exist as toV the size of the drill hole in which the blasting charge is received. Under such conditions where it is necessary that the cartridge unitbe of the smallest practical outside dimensions, it is a Aconsiderable problem to provide thequantity of high pressure gas required to perform the desired work. It is possible, of course, to increase the depth of the drill hole and the length of the cartridge substantially within practical limits, but diculty arises due to the fact that there is a distinct limit to the volume of 4 high pressure gas which can be applied to the work through a single discharge orice of the maximum size obtainable in a cartridge unit of relatively restricted external dimensions, 'Ihe speed of application of the form of energyunder consideration is an all important factor, and

this, of course, is determined by the relation between the volume of the gas to be applied and the size of the Ydischarge orice through which it must be applied.

- An object of the present invention is to provide a cartridge unit of relatively small outside dimensions which overcomes to a great extent the difficulties above outlined. Another object is to provide a. cartridge unit of an improved design wherein with a. relatively small outside diameter a relatively large amount of energy may be applied to the work. provide an improved blasting cartridge having relatively large capacity storing means for the gas to be applied to' the work,`together with pres- 40 sure release means having a relatively large discharge flow area whereby the blasting energy may be more advantageously applied to the work.

Yet another object is to providec an improved blasting cartridge of the type designed foruse with high pressure gas as a blasting medium having improved multiple discharge 'means for effecting sudden release of a relatively large volume of high pressure gas. Yet another object is to provide an improved blasting cartridge of the simultaneous, multiple discharge type wherein with a cartridge unit of extremely small cross sectional area a relatively large volume of blasting pressure is applied to the work. Still another object is to provide an improved blasting car- 55 tridge of the simultaneous, multiple discharge A further object is to type wherein the pressure discharge means are arranged near the central portion of the cartridge whereby the blasting pressure may be effectively applied to the work. A still further object is to provide an improved blasting cartridge of the simultaneous, multiple discharge type having a plurality of pressure containing chambers, together with improved mechanism for simultaneously releasing the blasting charges from said chambers. A still further object of this invention is to provide an improved blasting cartridge for applying the maximum amount of high pressure gas to the work, in cases where rigid limitations exist as to the outside dimensions of the cartridge, that is, when it is necessary that the pressure container be of the smallest practical outside diameter, and wherein a relativelylarge volume of high pressure gas is necessary to attamthe desired blasting eiect. These and other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawing there is shown for purposes of illustration one form which the invention may assume in practice.

In this drawing,-

Fig. 1 is a view in longitudinal section illustrating the improved blasting cartridge.

Fig. 2 is a somewhat diagrammatic view showing the cartridge in blasting position in a mine wall.

In this illustrative construction there is shown a blasting ,cartridge of the type wherein a high pressure gas is employed as a. .blasting medium and comprising two container units l and 2 arranged end to end in axial alinement andA having pressure receiving chambers 3 and 4, respectively for receiving the separate charges of high pressure gas. The outer container I has threaded within its outer end a terminal cap 5 and threaded within its inner end a discharge cap 5, while the inner container 2 has threaded within its inner end a terminal cap 'I and threaded within its outer end a, discharge cap 8, and the adjacent discharge caps 6 and 8 of the two-container units are threadedly secured together at 9. .'Ihe discharge cap tfor the outer container I has an axial discharge orice IU terminating in radial discharge ports II, while the discharge cap 8 hasY a similar axial discharge rice I2 terminating in radial discharge ports I the discharge ports of the two container caps being arranged in aiacency near the central portion of the cartridge unit. Each of the containers I and 2 is provided with a differential valve mechanism for conning the charge of high pressure gas in the container chambers 3 and 4, and for simultaneously suddenly releasing the blasting, charge when a predetermined blasting pressure is attained within the cartridge unit. The particular type of difw ferential valve mechanism shown is similar in design to that disclosed in my copending application Ser. No; 718,175, filed March 30, 1934. The differential valve mechanisms are arranged within the containers in opposed end to end relation with the controlling valves thereof arranged in adjacency, to control the ow of gas through the discharge orices I0 and -I2 and have, respectively, control mechanisms arranged at the remote ends of the cartridge unit. The differential valve mechanism for the container I consists of a plunger |4 reciprocably mounted in the bore of a control chamber I5 formed in the terminal cap 5 and high pressure gas is supplied to this chamber from a suitable remote source through tubing I6 secured by a nipple Il Within the terminal cap 5. The body of this plunger has secured thereto by an adjustable keeper I8 a cup leather packing I9 for preventing flow of high pressure gas from the pressure chamber 3 to the control chamber I5 at the outer side of the plunger. This plunger is connected by a Valve rod 20, arranged axially Within the pressure chamber, to a conical control valve 2| seating upon a seat upon the wall`of the discharge orice Ill. Secured in place within the container by the terminal cap 5 is a heavy metal plate 22 having secured thereto a hat leather 23 engaging the exterior periphery of the rod 20 and functioning as a check valve for preventing leakage of gas from the control chamber I5 to the pressure chamber 3 while permitting flow from the chamber 3 to the control chamber at the inner side of the plunger. The conical valve 2| has an axial extension 24 which, together with a suitably formed bore in the discharge cap 6, serves to center and guide the valve. 'Ihe valve rod 20 is axially bored at 25, and this bore extends completely through the rod and communicates with the control chamber I5 through a passage 26 in the plunger body and through a passage 2'| in the valve and valve guide with a space 28 between the discharge caps 6 and 8, as shown in Fig. 1. Radial passages 29, check-Valved as by an expansible sleeve valve 30, connect the axial passage 25 with the pressure chamber 3. The diiTerential valve mechanism for the container 2 is of a similar design but oppositely acting so that the control valves move away from one another when the valves are opened to eect pressure release. This valve mechanism comprises a packed plunger 3| reciprocably mounted in a control chamber 32 in the terminal4 cap 'l and connected by a valve rod 33 to a conical control valve 34. This Valve seatson the inner Wall of the discharge orifice I2 and is provided with an axial extension 35 which, together with a suitably formed bore in the discharge cap 8', serves to center and guide the Valve. A heavy metal plate 36 secured to the container by the terminal cap 'I carries a. hat leather 31 functioning as a check Valve for preventing leakage of gas from the control charnber to the pressure chamber While permitting flow of gas from the pressure chamber to the control chamber at the outer side of the plunger. The valve rod is provided with an axial bore 38 and this bore extends completely through the rod and communicates through a passage 39 in the plunger body with the control chamber 32 at the inner sid'e of the plunger and through an axial passage 40 in the valve and valve guide with the space 23 between the discharge caps 6 and 8. The axial valve rod bore 38 communicate through radial passages 4I controlled by an v.' pansiole sleeve valve 42 with the pressure cham ber 4. The guide extensions 24 and 35 of the control valves are guided in packed bores in the discharge caps, the packings tightly engaging the guide extensions to prevent leakage of gas from the space 28 between the discharge caps.

In the use of the improved cartridge unit thc latter is rst inserted in the drill hole 43 formed in the working face of the coal seam and when the cartridge unit is suitably positioned within the drill hole the same is connected through the tubing I6 to a suitable remote source of high pressure gas. The drill hole extends substantially beyond the depth of the undercut 44 and this extra length of drill hole accommodates the inner portion of the cartridge unit beyond the discharge cap 8, locating the discharge ports II and I3 of the two containers at a point approximately above the inner end of the undercut in the manner shown in Fig. 2. Hence, a large volume oi high pressure gas in the pressure chambers may be exhausted with the greatest possible speed duc to the large flow area of the exhaust and hence with the greatest eiciency in terms of work per- -formed. When the cartridge is thus positioned,

high pressure gas may flow,- under the control of remote control means, through this tubing to f the control chamber I5 at the outer side of the plunger I4 and through the axial valve rod bore 25 and radial passages 29 past the control valve 30 to the pressure chamber 3, the pressure of the gas acting against 'the outer pressure area oi the *7' plunger I4 holding the discharge control valve 2| seated tightly against the inner wall of the discharge orifice I0. Simultaneously, gas flows through the valve rod bore and through the axial passage in the valve guide extension to the chamber 28, through the axial passage 40 and axial bore 38 in the Valve rod to the control chamber 32 at the inner side of the plunger 3|, and through radial passages 4I past the control valve 42 to the pressure chamber 4. The pressure of the gas acting on the inner pressure area of the plunger 3| maintains the discharge control valve 34 in tight seated engagement with the inner wall of the discharge orifice I2. When a predetermined blasting pressure is attained in the container phere or otherwise reduced. As a result, the gas owing from the chambers 3 and 4 past the hat leathers 23 and 21 acts on the inner pressure areas of the plungers to move the latter outwardly against the reduced opposing pressure, thereby to eiTect sudden unseating of the two discharge control valves 2| and 34, with the resultant simultaneous sudden release of the blasting charges through the discharge orifices I0 and I2 and radial discharge ports II and I3 in the adjacent discharge caps.

By the provision of the multiple discharge orices, together with the multiple pressure chambers in a single cartridge unit, it is possible to apply eiciently the maximum amount of high pressure gas to the work in cases where rigid limitations exist as to the external diameter of the cartridge unit. Further, by the provision of a plurality of container units having differential valve release means, a. relatively large volume of high pressure gas may be simultaneously released from the containers in an improved and more eiective manner. These and other uses and advantages of theirnproved blasting cartridge will be clearly apparent to those skilled in the art.

While I have in this application specically described one form which my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration, and that the invention may be modiiied and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secureby Letters Patent is:

1. In a blasting cartridge, a container unit having a plurality of charge receiving chambers,

a discharge VYdevice associated with each chamber ,and arranged at the adjacent ends bf said chamranged at the remote ends of said chambers for controlling said valves. i

3. In a blasting cartridge, a container unit having a plurality of charge receiving chambers having at their adjacent ends discharge orifices, Valves Within the adjacent ends of the containers for controlling saiddischarge orices, and pressure iluid controlled means for controlling said discharge valves including control chambers arranged at the remote ends of the containers, a plunger recprocable in each control chamber and connected to said valves respectively.

4. In a blasting cartridge, a container of relatively great length and relatively small external diameter, means dividing said container into two separate charge receiving chambers, each chamber having a discharge orifice, and pressure uid f controlled valve means for governingsaid orifices respectively, thus providing the most emcient relation between the volumetric capacity of the chambers and the area of the discharge orice therefor, and pressure fluid controlling means for said valve means including control chambers varranged at the remote ends of said containers and plungers reciprocable in said control chambers and connected to said valves respectively.

5. In a. blasting cartridge, an elongated con- `tainer unit having a plurality of charge receiving chambers, pressure discharge means arranged ranged at the outer end of the container unit for charging said chambers.

'1. In a blasting cartridge. a container unit s. having a pair of charge receiving chambers,

charge release means at the adjacent ends of said chambers, valves at 'the adjacent ends of said chambers for controlling said release means, and control means for said valves including control elements arranged at the remote ends of said chambers, a plunger reciprocable in each control chamber, and valve rods connecting said plungers to said valves, respectively.

8. In a blasting cartridge, a container unit having a pair of charge receiving chambers, charge release means at the adjacent ends of said chambers, valves at the adjacent ends of said chambers for controlling said release means, control means for said valves including control elements arranged at the remote ends of said chambers, a plunger reclprocable in each control chamber and valve rods connecting said plungers to said valves, respectively, and means for charging said chambers comprising a connection at the outer end of the container unit and including passage means formed in the valve rod and valve of the outer chamber for supplying blasting pressure to the inner chamber.

9. In a blasting cartridge, a container unit having a plurality of charge receiving chambers, a valve release mechanism for each chamber, and separate differential pressure means for operating each of said valve mechanisms to effect simultaneous release of the blasting charges from said chambers, said separate means being located at the remote ends of said chambers.

l0. In a blasting cartridge, a container unit having a pair of pressure receiving chambers, means for eiIecting simultaneous release of the blasting charges from said chambers, and charging means for said chambers, the charging means for one chamber including a charging passage formed in an element of the pressure release means for the other chamber.

11. In a blasting cartridge, an elongated container unit having a pair of charge receiving chambers, and means for eectlng charge release from said chambers including like elements for each chamber, namely a discharge valve and a discharge valve control means respectively arranged at the opposite ends of the chamber with which they are associated, two of the like elements arranged adjacent to each other and the other two like elements spaced from each other by the combined lengths of the chambers.

l2. In a blasting cartridge, anelongated container unit having a pair of charge receiving chambers, and means for storing fluid blasting charges in each chamber and effecting subsequent release of such charges at will including for each chamber a charge retaining valve and means for opening the same to eiect charge release, one of said valves providing a .passage for conducting a iiuid blasting charge to the chamber with which the other cooperates.

FRANK H. ARMSTRONG. 

